The Lower Brule Sioux Tribe will not be required to pay back nearly $1.5 million in missing taxpayer funds, prompting concerns from two members of the state’s congressional delegation and the organization that uncovered widespread financial mismanagement.

The U.S. Bureau of Reclamation announced that the tribe will only be required to pay back $54,190. The decision comes six months after the Office of Inspector General for the Interior Department released an audit into the tribe’s spending on the Mni Wiconi Rural Water Project. The OIG audit found a host of problems, including tribal council members paying themselves extra money, including for meetings they didn’t attend, and others receiving tens of thousands of dollars in “additional compensation” that was not documented to show what they did to earn the money.

The audit also faulted the Bureau of Reclamation, which administered the Mni Wiconi project, for not providing oversight in how the tribe spent taxpayer dollars.

The audit was one of several federal reviews after Human Rights Watch published a lengthy investigation that documented millions of dollars in taxpayer funds being diverted from their original purposes by tribal leaders. Another audit found hundreds of thousands of dollars in questionable payments and lax oversight by the Bureau of Indian Affairs.

Arvind Ganesan, the director of the business and human rights division of Human Rights Watch, said the OIG audit found more than $1.4 million in misused taxpayer funds and it found that both the Bureau of Reclamation and the tribe were at fault.

“Since more than $100k of the misused money went to unauthorized bonuses, compensation, and entertainment, the bureau and tribe need to explain why they only have to repay about $54,000 of the $1.4 million the OIG said was misspent,” Ganesan said in an email.

Michael Ryan, the Bureau of Reclamation’s Great Plains regional director, said in a press release that the bureau and tribe worked together to reach a number that the tribe would repay.

“Reclamation made a decision after careful review of the facts and findings of the audit, while staying in close coordination with the tribe,” Ryan said.

The decision to require the tribe to only pay back $54,000 is “concerning,” Rep. Kristi Noem said.

“The misuse of taxpayer dollars must be taken seriously, so the Bureau of Reclamation’s announcement is concerning,” Noem said. “Taxpayers deserve a better explanation of the rationale behind this decision.”

Sen. John Thune called the misuse of taxpayer funds “serious and unacceptable.”

“While I’m still reviewing some of the details, this is clearly an opportunity to improve internal controls and agency oversight to ensure that taxpayers’ hard-earned money is being used efficiently and for its intended purposes – which in this case is to provide clean water to the community.”

Sen. Mike Rounds said in a statement that the bureau made its decision based on its findings and that the tribe has agreed to strengthen oversight. “We will continue monitoring the situation while the project moves forward to provide safe, reliable water to our communities,” Rounds said.